We denote by \(P_{\infty }\)  as the solution to \(\mbox{\rm Ricc}(P_{\infty })=0\) .
Set \(\mu (A-P_{\infty }S)\)  as the largest eigenvalue of \(\tfrac{1}{2}(A-P_{\infty }S+(A-P_{\infty }S)^{\prime })\) .
For the case of (), the following result, presented in [1]}, can be shown.
